The effects of the dressing rate of nitrogen fertilizer on rice morphological characteristics and grain yield and quality were studied, so as to clarify the optimal dressing rate of nitrogen fertilizer for rice variet...The effects of the dressing rate of nitrogen fertilizer on rice morphological characteristics and grain yield and quality were studied, so as to clarify the optimal dressing rate of nitrogen fertilizer for rice variety Shengdao 735. Six nitrogen appli- cation rates （No （0 kg/hm2）, N1 （69 kg/hm2）, N2 （138 kg/hm2）, N3 （207 kg/hm2）, N4 （276 kg/hm2） and N~ （345 kg/hm2）） were designed. The results showed that with the increase of the nitrogen application rate, the protein content and amylase content of rice increased; the plant height, tiller number, effective panicle number per hill and grain yield increased at first and decreased then; and the grain number per panicle, 1 000-grain weight and taste value decreased. The brown rice rate, head rice rate and chalky kernel percentage did not change significantly. Shengdao 735 gave the highest production in N4 treatment the nitrogen application rate of which was 276 kg/hm2. The result of regression analysis showed that the grain yield and economic benefit were the highest in treatment N4. The nitrogen fertilizer rate of 276 kg/hm2 was suitable for Shengdao 735.展开更多
Calculation and comparative study of the chlorophyll fluorescence ratio F685/F735 in brown algae (Laminaria japonica, Underia pinnatifida and Padina crassa) excited by blue and green light showed that the fluorescence...Calculation and comparative study of the chlorophyll fluorescence ratio F685/F735 in brown algae (Laminaria japonica, Underia pinnatifida and Padina crassa) excited by blue and green light showed that the fluorescence ratios were higher when the algae were excited by blue light (440 nm), but reduced obviously under green light (540 nm) excitation. The values also reduced under dehydration but could recover during rehydration if the stress was not serious. The variation of the fluorescence ratio under dehydration was mainly because changes in fluorescence emission at 735 nm were always sharper than those at 685 nm. The ratio was sensitive to stress and has potential as a stress indicator in phycological research. Measurement of the fluorescence excitation spectra showed that the only peak at 540 hm changed apparently during dehydration. It meant that the function of the Chl a /Fucoxanthin protein complex for energy transfer was easily inhibited by water stress. However, no variation of the ratio was展开更多
文摘The effects of the dressing rate of nitrogen fertilizer on rice morphological characteristics and grain yield and quality were studied, so as to clarify the optimal dressing rate of nitrogen fertilizer for rice variety Shengdao 735. Six nitrogen appli- cation rates （No （0 kg/hm2）, N1 （69 kg/hm2）, N2 （138 kg/hm2）, N3 （207 kg/hm2）, N4 （276 kg/hm2） and N~ （345 kg/hm2）） were designed. The results showed that with the increase of the nitrogen application rate, the protein content and amylase content of rice increased; the plant height, tiller number, effective panicle number per hill and grain yield increased at first and decreased then; and the grain number per panicle, 1 000-grain weight and taste value decreased. The brown rice rate, head rice rate and chalky kernel percentage did not change significantly. Shengdao 735 gave the highest production in N4 treatment the nitrogen application rate of which was 276 kg/hm2. The result of regression analysis showed that the grain yield and economic benefit were the highest in treatment N4. The nitrogen fertilizer rate of 276 kg/hm2 was suitable for Shengdao 735.
基金This work is supported by a fellowship of the EMBL(The Experimental Marine Biological Laboratory,Institute of Oceanology,Academia Sinica)
文摘Calculation and comparative study of the chlorophyll fluorescence ratio F685/F735 in brown algae (Laminaria japonica, Underia pinnatifida and Padina crassa) excited by blue and green light showed that the fluorescence ratios were higher when the algae were excited by blue light (440 nm), but reduced obviously under green light (540 nm) excitation. The values also reduced under dehydration but could recover during rehydration if the stress was not serious. The variation of the fluorescence ratio under dehydration was mainly because changes in fluorescence emission at 735 nm were always sharper than those at 685 nm. The ratio was sensitive to stress and has potential as a stress indicator in phycological research. Measurement of the fluorescence excitation spectra showed that the only peak at 540 hm changed apparently during dehydration. It meant that the function of the Chl a /Fucoxanthin protein complex for energy transfer was easily inhibited by water stress. However, no variation of the ratio was
